<?php

declare(strict_types=1);

namespace App\Administration\Application\Query\GetParentInvitations;

use App\Administration\Application\Dto\PaginatedResult;
use App\Administration\Domain\Model\Invitation\InvitationStatus;
use App\Administration\Domain\Model\User\UserId;
use App\Administration\Domain\Repository\ParentInvitationRepository;
use App\Administration\Domain\Repository\UserRepository;
use App\Shared\Domain\Tenant\TenantId;

use function array_filter;
use function array_map;
use function array_slice;
use function array_values;
use function count;
use function mb_strtolower;
use function str_contains;

use Symfony\Component\Messenger\Attribute\AsMessageHandler;
use Throwable;

#[AsMessageHandler(bus: 'query.bus')]
final readonly class GetParentInvitationsHandler
{
    public function __construct(
        private ParentInvitationRepository $invitationRepository,
        private UserRepository $userRepository,
    ) {
    }

    /**
     * @return PaginatedResult<ParentInvitationDto>
     */
    public function __invoke(GetParentInvitationsQuery $query): PaginatedResult
    {
        $tenantId = TenantId::fromString($query->tenantId);

        $invitations = $this->invitationRepository->findAllByTenant($tenantId);

        if ($query->status !== null) {
            $filterStatus = InvitationStatus::tryFrom($query->status);
            if ($filterStatus !== null) {
                $invitations = array_filter(
                    $invitations,
                    static fn ($inv) => $inv->status === $filterStatus,
                );
            }
        }

        if ($query->studentId !== null) {
            $filterStudentId = UserId::fromString($query->studentId);
            $invitations = array_filter(
                $invitations,
                static fn ($inv) => $inv->studentId->equals($filterStudentId),
            );
        }

        // Build a student name cache for search and DTO enrichment
        $studentNames = $this->loadStudentNames($invitations);

        if ($query->search !== null && $query->search !== '') {
            $searchLower = mb_strtolower($query->search);
            $invitations = array_filter(
                $invitations,
                static function ($inv) use ($searchLower, $studentNames) {
                    $studentId = (string) $inv->studentId;
                    $firstName = $studentNames[$studentId]['firstName'] ?? '';
                    $lastName = $studentNames[$studentId]['lastName'] ?? '';

                    return str_contains(mb_strtolower((string) $inv->parentEmail), $searchLower)
                        || str_contains(mb_strtolower($firstName), $searchLower)
                        || str_contains(mb_strtolower($lastName), $searchLower);
                },
            );
        }

        $invitations = array_values($invitations);
        $total = count($invitations);

        $offset = ($query->page - 1) * $query->limit;
        $items = array_slice($invitations, $offset, $query->limit);

        return new PaginatedResult(
            items: array_map(
                static function ($inv) use ($studentNames) {
                    $studentId = (string) $inv->studentId;

                    return ParentInvitationDto::fromDomain(
                        $inv,
                        $studentNames[$studentId]['firstName'] ?? null,
                        $studentNames[$studentId]['lastName'] ?? null,
                    );
                },
                $items,
            ),
            total: $total,
            page: $query->page,
            limit: $query->limit,
        );
    }

    /**
     * @param iterable<\App\Administration\Domain\Model\Invitation\ParentInvitation> $invitations
     *
     * @return array<string, array{firstName: string, lastName: string}>
     */
    private function loadStudentNames(iterable $invitations): array
    {
        $studentIds = [];
        foreach ($invitations as $inv) {
            $studentIds[(string) $inv->studentId] = true;
        }

        $names = [];
        foreach ($studentIds as $id => $_) {
            try {
                $student = $this->userRepository->get(UserId::fromString($id));
                $names[$id] = [
                    'firstName' => $student->firstName,
                    'lastName' => $student->lastName,
                ];
            } catch (Throwable) {
                $names[$id] = ['firstName' => '', 'lastName' => ''];
            }
        }

        return $names;
    }
}